CMake: Add add_subdirectory of unittests

- add every libraries unittest directory into respective CMake
  which allows to include unittest source into build based on
  MBED_BUILD_UNITTESTS flag

connectivity/cellular/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 add_subdirectory(source/framework)
 
 target_include_directories(mbed-cellular

connectivity/lorawan/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 add_subdirectory(lorastack)
 add_subdirectory(system)
 

connectivity/netsocket/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 # TODO CMake: Perhaps move this/these file(s) into connectivity/drivers/cellular
 target_sources(mbed-cellular
     INTERFACE

drivers/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 target_include_directories(mbed-core
     INTERFACE
         .

events/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 add_library(mbed-events INTERFACE)
 
 target_include_directories(mbed-events

platform/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 # List of all optional platform libraries available.
 add_library(mbed-psa INTERFACE)
 

storage/blockdevice/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 if("DATAFLASH" IN_LIST MBED_TARGET_LABELS)
     add_subdirectory(COMPONENT_DATAFLASH)
 endif()

storage/kvstore/filesystemstore/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 target_include_directories(mbed-storage-filesystemstore
     INTERFACE
         .

storage/kvstore/tdbstore/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(NOT ${CMAKE_CROSSCOMPILING})
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 target_include_directories(mbed-storage-tdbstore
     INTERFACE
         .